Electronic devices often include a clock for providing information about time. For example, it is desirable for electronic devices that perform security functions to have a means for obtaining date and time information. For forensic logging functions, it is important to have the capability of logging the times of certain events.
A real time clock keeps track of the current time even when the device is turned off. A real time clock therefore requires a source of power, such as a battery, that allows the clock to continue to function and keep time after the device is powered down. In contrast, clocks that are not real time do not function when the device is turned off but keep time fairly accurately when powered-up.
A problem common to many electronic devices, such as storage devices, is that it is often impractical to include a real time clock for cost reasons or reasons of practicality around the need for power. This makes it difficult to maintain accurate time information and to log a precise order of events so that evidence as to what even occurred and when the event occurred cannot be easily repudiated.
A clock architecture is therefore desired that is capable of providing electronic devices with at least some clock information that can be used to reliably order events without the need for constant power, depending on the context of the device and the context of use.
One or more embodiments of the present invention provide solutions to these and other problems, and offer other advantages over the prior art.